System And Method For Manufacturing A Honeycomb Body

ABSTRACT

A system and method for manufacturing a honeycomb body is described provided. Said system having: a forming mold with a plurality of sub-molds, which are movable so that they can be opened and closed; a tightening mold for tightening said forming mold; rolling pin(s), which can be inserted into and pulled out of the inner volume of said forming mold and can rotate around a rotation axis; wherein said tightening mold has a shape that cooperates with the shape of said forming mold, so that an action of said tightening mold causes tightening of said forming mold.

TECHNICAL FIELD

The present invention relates to a system and a method for manufacturinga honeycomb body, more specifically, to system and method formanufacturing an S-type metal honeycomb body.

BACKGROUND

Honeycomb bodies are commonly used in many fields, such as filters,catalyst substrates in the engine exhaust purification system. Honeycombbody has large channel surface area, low back pressure, excellentmechanical performance and catalysis engineering specialty. In recentyears, S-type metal honeycomb body is of particular concern.

Metal honeycomb body is usually made of metal foil. The honeycombstructure needs to be continuously tightened so as to define theinternal channels of the honeycomb structure. The precision of thehoneycomb body manufacturing will affect its life and other properties.

Device and method for manufacturing a honeycomb body is known form thestate of art. For example, WO97/10135 describes a device and a methodfor manufacturing a honeycomb body. The device includes a fork rollingmechanism, which rotates around an axis and holds the foil stack, and anarc mold segment, which can close to form a mold. The model consists ofat least two mold segments, which can rotate around their axesrespectively. The axes of rotation are parallel with the rolling axisrespectively. In CN 101251036A also a device and a method formanufacturing a honeycomb body are known. The device includes a fixedpost and two sets of mold segments, which can be closed to form a mold.These devices are not only complex, difficult to manufacture, and alsolack of accuracy.

U.S. Pat. No. 7,318,276B2 discloses a method for finish machining ahoneycomb body, wherein the honeycomb structure are processed by meansof fine-processing tools after being rolled, so as to meet the requiredperformance.

Some of the technical solutions in the art either lead to inadequateperformance of honeycomb body and even waste products due the inaccuracyof the honeycomb body's shape. Other solutions, in spite of enhancingthe manufacturing precision, cause high complexity in configuration,difficulty in accurate control, and/or high costs in the manufacturingprocess.

SUMMARY OF THE INVENTION

The invention is based on the purpose to provide a system forautomatically manufacturing a honeycomb body; the system has simplestructure and can produce honeycomb bodies with good stability and longlife.

According to the invention, the system includes a forming mold with aplurality of sub-molds, which are movable so that they can be opened andclosed; a tightening mold for tightening said forming mold, i.e. forclosing the sub-molds thereof; rolling pin(s), which can be insertedinto and pulled out of the inner volume of said forming mold and canrotate around a rotation axis. According to this invention, saidtightening mold has a shape that cooperates with the shape of saidforming mold, so that an action of said tightening mold causestightening of said forming mold.

By means of this system, the honeycomb structure can be manufacturedwith high accuracy without using complex tightening system, such asthose in the prior art.

According to a preferred embodiment, said forming mold has a conicalouter surface, which cooperates with a conical inner surface of saidtightening mold, and said tightening mold are displaced in the axialdirection in the action. This solution is preferred since the tighteningmold can be easily and precisely controlled. Thus, not only thetightening mold itself, but also the driving train thereof, can besimply constructed and manufactured with low cost. This tightening moldcan be easily driven, for example, by an electric motor via a gear-racktransmission, worm transmission and the like.

Other solutions are also possible for providing the forming mold and thetightening mold with cooperating configurations, such as matingstructures with thread or groove and the like.

The forming mold preferably comprises four sub-molds. But a forming moldwith only two, six or more sub-molds is also conceivable, that leads toa simpler solution. More sub-molds bring more evenly distributed actingforce to the honeycomb body, but also brings more complexity to thestructure.

Preferably, the sub-molds can be closed to form a cylindrical,circumferential closed inner volume. This solution brings the advantage,that the final size of the honeycomb structure is controlled preciselymerely by the geometry characters of the sub-molds. Thus a manufacturingsystem with high accuracy can be provided easily.

According to a preferred embodiment, the manufacturing system furthercomprises an ejecting part, which is movable in the axial direction soas to push the rolled-up honeycomb structure into a housing. Thus ahighly automated system is achieved.

Also for the purpose of providing a highly automated system, a automaticfeeding device for feeding said forming mold with foil stack to berolled is provided.

A method for manufacturing honeycomb body by using the above describedsystem is also suggested. The method comprises the following steps:

opening the forming mold;

introducing the foil stack into the space between the rolling pins;

rotating the rolling pins until the foil stack is fully rolled into theforming mold;

rotating the rolling pins while activating the tightening mold, with theaction thereof causing the inner volume of the forming mold decreasingto a first value;

pulling the rolling pins out of the structure formed by the foil stack;

pushing the rolled-up honeycomb structure into a housing by means of theejecting part.

By means of this method, honeycomb bodies can be automatically producedwith high accuracy. The produced honeycomb bodies have gut behavior andlong life, because of this precisely controlled process, in which thehoneycomb structure is tightened while being rolled up.

Preferably, a further step is provided between the step of pulling therolling pins out and the step of pushing the rolled-up honeycombstructure into a housing, in which the tightening mold further functionsso as to cause the inner volume of the forming mold decreasing to asecond value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of the system according to the invention;

FIG. 2 is a section of the manufacturing system, with the system in astate when the foil stack is being introduced;

FIG. 3 is a drawing of the system according to the invention lookingfrom the arrow D in FIG. 2;

FIG. 4 is a drawing corresponding to FIG. 2, with the foil stack beingalready rolled and the tightening mold being already crossed a distance;

FIG. 5 is a drawing corresponding to FIG. 3, with the foil stack beingalready rolled and the tightening mold being already crossed a distance;

FIG. 6 is a block diagram showing the process for manufacturing ahoneycomb body.

DETAILED DESCRIPTION

FIG. 1 shows a system for manufacturing a honeycomb according to theinvention. The system includes a frame, driving trains, a forming mold 1for rolling volume of the honeycomb-type and tightening mold 6.

FIGS. 2 and 3 show a section of the system for manufacturing a honeycombaccording to the invention. The forming mold 1 consists of foursub-molds independent of each other (see FIG. 3), which four sub-moldscan be opened and closed. For example, the four sub-molds are supportedon the frame like the jaws of a four-jaw chuck. The sub-molds arepreferably movable in the radial direction in their own slide railsrespectively. The sub-molds are biased to the direction of opening bysprings. The four sub-molds can naturally be arranged in other knownmeans.

As can be seen from FIG. 3, there are gaps between the four sub-molds Ain their opening state, through which gap a foil stack 3 to be rolledcan be introduced into the forming mold 1. The foil stack 3 is producedby stacking wave metal foils and flat metal foils alternatively.

In the present embodiment, the four sub-molds of the forming mold 1 arehold in a tightening mold 6. The forming mold 1 includes a conical outersurface, which engages with a conical inner surface of the tighteningmold 6 in such a way, that the he forming mold 1 are contractedcontinuously by the axial movement (shown by arrow D) of the tighteningmold 6. That result in the tightening of the honeycomb lying in theforming mold 1, see FIG. 4 and FIG. 5. In one embodiment, the foursub-molds can be contracted to form a close cylindrical cavity.

The forming mold 1 and the tightening mold 6 engage with each otherpreferably by matched conical surfaces thereof. But engagements withother matched shapes can also be envisaged.

The system shown in FIG. 1 includes rolling pins 2, which can beinserted into the inner volume of the forming mold 1. In the shownembodiment, two rolling pins 2 are provided so as to manufacture adouble S-shaped honeycomb structure. Other conventional arrangements ofthe rolling pins for manufacturing corresponding honeycomb structure arealso possible.

One end of the rolling pin 2 is supported in a pin driving shaft 7. Thepin driving shaft 7 can rotate around its longitudinal axis. The rollingpins are driven by the pin driving shaft 7 in such a way, that theyrotate around an axis X, which is parallel to both of the rolling pins2. The axis X of the rolling pins locates in the center of the formingmold 1 and is equally distanced from the rolling pins 2. The foil stack3 is rolled up by the rotation of the rolling pins 2 and form anS-shaped honeycomb structure. The pin driving shaft 7 can by movedaxially to a first position, in which the rolling pins 2 are insertedinto the volume of the forming mold 1, and a second position, in whichthe rolling pins 2 are pulled out of the volume.

The system 10 also includes an ejecting part 5, which can slide on thepin driving shaft 7 so as to push the rolled honeycomb structure into anhousing 8. Thus, a honeycomb is manufactured. In FIG. 5, the centralpart of the foil stack 3, which has been rolled as a honeycombstructure, is coved by the ejecting part 5.

In one embodiment, a supporting shaft 4 for supporting the rolling pins2 is provided on the other side of the rolling pins 2. The housing 8 ispushed on the supporting shaft 4. The supporting shaft 4 is axiallymovable, such that it can leave the housing 8 when the honeycombstructure is pushed out by the ejecting part 5.

The mechanics of the manufacturing system, i.e. the manufacturing methodis described below:

First, the foil stack 3 is prepared. Usually a foil stack 3 is formed bysimply stacking a certain number of wave foils and flat foils. Then ahousing 8 for honeycomb is placed into the manufacturing system. Formetal honeycomb bomolds, the housing is usually a steel sleeve.

In step S01, the forming mold 1 is opened.

In step S02, a foil stack 3 is introduced into the space between the tworolling pins 2 through the gap between two sub-molds, see FIG. 2 andFIG. 3.

In step S03, the rolling pin driving shaft 7 is rotated by the drivingtrain. The rolling pins 2 are rotated by the rolling pin driving shaft 7as such, that the foil stack 3 is rolled into the forming mold 1.

In a step S04, the tightening mold 6 is moved axially, so that the innervolume of the forming mold 1 gradually decreases to a first value, afterthe foil stack 3 is completely rolled into the forming mold 1. In themean time, the rolling pins 2 keep rotating. In this embodiment, thetightening mold 6 moves linearly in a direction D in its tighteningaction. Due to the engagement of the conical inner surface of thetightening mold 6 with the conical outer surface of the forming mold 1,the sub-molds of the forming mold 1 are displaced inwardly in radialdirection by the axial movement of the tightening mold 6, tightening thehoneycomb structure formed by the foil stack 3, see FIG. 4 and FIG. 5.

In a step S05, the rolling pins 2 is pulled out after S04, and thetightening mold 6 is further moved, so that the inner volume of theforming mold 1 further decreases to a second value.

In a step S06, after the second value is reached, the ejecting part 5pushes the rolled-up honeycomb structure into a housing, so that ahoneycomb with a housing and a rolled-up honeycomb structure is formed.In particular, the second value corresponds to the inner size of theforming mold 1 with the four sub-molds fully closed.

LIST OF SYMBOLS

-   1 forming mold-   2 rolling pins-   3 foil stack-   4 rolling pin driving shaft-   5 ejecting part-   6 tightening mold-   7 supporting shaft-   8 housing

1. A system for manufacturing a honeycomb body, comprising: a formingmold with a plurality of sub-molds, which are movable so that they canbe opened and closed; a tightening mold for tightening said formingmold; rolling pin(s), which can be inserted into and pulled out of theinner volume of said forming mold and can rotate around a rotation axis;wherein said tightening mold has a shape that cooperates with the shapeof said forming mold, so that an action of said tightening mold causestightening of said forming mold.
 2. The system of claim 1, wherein saidtightening mold has a conical inner surface, which cooperates with aconical outer surface of said forming mold, and said tightening mold aredisplaceable in the axial direction.
 3. The system of claim 1, whereinsaid forming mold comprises four sub-molds.
 4. The system of claim 1,wherein said sub-molds can be closed to form a cylindrical,circumferential closed inner volume.
 5. The system of claim 1, furthercomprising an ejecting part, which is movable in the axial direction soas to push the rolled-up honeycomb structure into a housing.
 6. Thesystem of claim 1, further comprising a rolling pin driving shaft, whichsupports one end of the rolling pin, and on which said ejecting part isarranged, such that said ejecting part is slidable on the rolling pindriving shaft.
 7. The system of claim 1, further comprising a automaticfeeding device for feeding said forming mold with foil stack to berolled.
 8. A method for manufacturing honeycomb body, wherein the systemof one of the above claims is applied, the method comprising thefollowing steps: opening the forming mold; introducing the foil stackinto the space between the rolling pin; rotating the rolling pins untilthe foil stack is fully rolled into the forming mold; rotating therolling pins while activating the tightening mold, with the actionthereof causing the inner volume of the forming mold decreasing to afirst value; pulling the rolling pins out of the structure formed by thefoil stack; pushing the rolled-up honeycomb structure into a housing bymeans of the ejecting part.
 9. A method of claim 8, wherein a furtherstep is provided between the step of pulling the rolling pins out andthe step of pushing the rolled-up honeycomb structure into a housing, inwhich the tightening mold further functions so as to cause the innervolume of the forming mold decreasing to a second value.